Gregory the Great
Catena Aurea · Matthäusevangelium 12
When the unclean spirit is gone out of a man, he walketh through dry places, seeking rest, and findeth none. Then he saith, I will return into my house from whence I came out; and when he is come, he findeth it empty, swept, and garnished. Then goeth he, and taketh with himself seven other spirits more wicked than himself, and they enter in and dwell there: and the last state of that man is worse than the first. Even so shall it be also unto this wicked generation.
(Mor. vii. 17.) For it often happens that the soul in the commencement of its progress is lifted up, and prides itself on its virtues, that it opens an entrance to the adversary who is raging against it, and who shews himself the more violent in breaking into it, by how much he was grieved at being cast out, though but for a short space.